System and method for providing sealing arrangement in X-ray tube

Abstract

A system and method for providing a sealing arrangement in an X-ray tube are provided. The X-ray tube includes a rotating portion having a plurality of ball bearings and a liquid metal within a housing having the ball bearings therein. The rotating portion is configured to rotate an anode. The X-ray tube further includes a sealing portion formed by a liquid metal vacuum interface configured in a radial direction to resist flow of liquid metal from the housing to a vacuum portion.

1. An X-ray tube comprising:
 a radially inner rotating portion having a plurality of ball bearings, the rotating portion configured to rotate an anode coupled to said rotating portion, wherein the rotating portion further comprises a shaft having a flange portion extending from an axis along a length of the shaft towards a direction of a radius of the shaft; 
 a liquid metal within a housing having the ball bearings therein; and 
 a liquid metal vacuum interface configured to resist a flow of the liquid metal from the housing to a vacuum portion, the liquid metal vacuum interface having a first sealing portion forming a vacuum seal in a radial direction and a second sealing portion forming a vacuum seal in an axial direction, wherein the flange portion forms a portion of the liquid metal vacuum interface. 
 
   
   
     2. An X-ray tube in accordance with  claim 1  wherein the first sealing portion comprises a radial interface and the second sealing portion comprises an axial interface together forming the liquid metal vacuum interface. 
   
   
     3. An X-ray tube in accordance with  claim 2  wherein the first sealing portion is configured as a primary sealing portion and the second sealing portion is configured as a secondary sealing portion. 
   
   
     4. An X-ray tube in accordance with  claim 2  wherein the radial interface is formed by at least one axial clearance portion and the axial interface is formed by at least one radial clearance portion. 
   
   
     5. An X-ray tube in accordance with  claim 4  wherein the at least one axial clearance portion is generally larger than the at least one radial clearance portion. 
   
   
     6. An X-ray tube in accordance with  claim 4  wherein the at least one axial clearance portion and one radial clearance portion comprise at least one capillary. 
   
   
     7. An X-ray tube in accordance with  claim 4  wherein the at least one axial clearance portion and one radial clearance portion form a labyrinth structure. 
   
   
     8. An X-ray tube in accordance with  claim 4  wherein a dimension of the at least one axial clearance portion and one radial clearance portion is determined based on surface tension of the liquid metal. 
   
   
     9. An X-ray tube in accordance with  claim 1  further comprising a plurality of grooves formed on at least one of (i) a shaft of the rotating portion, (ii) a flange extending from a shaft of the rotating portion, and (iii) a face of a seal cap facing a flange extending from a shaft of the rotating portion. 
   
   
     10. An X-ray tube in accordance with  claim 9  wherein the plurality of grooves are configured in an arrangement opposite in direction to a rotation of the rotating portion. 
   
   
     11. An X-ray tube in accordance with  claim 1  wherein the liquid metal comprises one of a gallium alloy, pure gallium, indium, and a tin alloy. 
   
   
     12. An X-ray tube in accordance with  claim 1  wherein the liquid metal vacuum interface comprises a non-contact seal forming a gap between the rotating portion and the housing having the ball bearings therein, the non-contact seal configured to prevent the liquid metal from flowing to the vacuum portion. 
   
   
     13. An X-ray tube in accordance with  claim 1  wherein the first sealing portion comprises a seal formed by centrifugal force acting on said liquid metal that contacts the housing. 
   
   
     14. An X-ray tube comprising:
 a radially inner rotating portion having a plurality of ball bearings, the rotating portion configured to rotate an anode coupled to said rotating portion, the rotating portion further comprising a shaft having a flange portion extending therefrom and forming a portion of a liquid metal vacuum interface; 
 a liquid metal within a housing having the ball bearings therein; and 
 a sealing portion formed by the liquid metal vacuum interface configured to resist a flow of the liquid metal from the housing to a vacuum portion, the liquid metal vacuum interface having a first sealing portion forming a vacuum seal in a radial direction and a second sealing portion forming a vacuum seal in an axial direction. 
 
   
   
     15. An X-ray tube in accordance with  claim 14  wherein the flange portion is configured in a radial arrangement. 
   
   
     16. A sealing arrangement for an X-ray tube, the sealing arrangement comprising:
 a radial vacuum interface between a radially inner rotating portion of an X-ray tube and a vacuum portion of the X-ray tube, wherein said radially inner rotating portion is coupled to an anode of the X-ray tube, and wherein the radially inner rotating portion further comprises a shaft having a flange portion extending from an axis along a length of the shaft towards a direction of a radius of the shaft; 
 an axial vacuum interface connected to the radial vacuum interface; and 
 a liquid metal within the rotating portion, the radial vacuum interface and the axial vacuum interface together configured to prevent flow of the liquid metal to the vacuum portion, wherein the flange portion defines the radial interface. 
 
   
   
     17. A sealing arrangement in accordance with  claim 16  wherein the radial interface comprises a non-contact seal. 
   
   
     18. A sealing arrangement in accordance with  claim 16  wherein the radial interface is formed by at least one axial clearance portion and wherein the axial interface is formed by at least one radial clearance portion. 
   
   
     19. A sealing arrangement in accordance with  claim 16  wherein the radial interface comprises a plurality of grooves configured in an arrangement in a direction opposite to a rotation of the rotating portion. 
   
   
     20. A sealing arrangement in accordance with  claim 16  wherein the liquid metal comprises a gallium alloy. 
   
   
     21. A sealing arrangement for an X-ray tube, the sealing arrangement comprising:
 a radial vacuum interface between a radially inner rotating portion of an X-ray tube and a vacuum portion of the X-ray tube, wherein said radially inner rotatina portion is coupled to an anode of the X-ray tube; 
 an axial vacuum interface connected to the radial vacuum interface; 
 a liquid metal within the rotating portion, the radial vacuum interface and the axial vacuum interface together configured to prevent flow of the liquid metal to the vacuum portion; and 
 a flange extending from a shaft of the rotating portion and defining the radial interface. 
 
   
   
     22. A rotating device comprising:
 a radially inner rotating portion having a plurality of ball bearings, the rotating portion configured to rotate an anode coupled to said rotating portion, and wherein the rotating portion further comprises a shaft havin a flange portion extending from an axis along a length of the shaft towards a direction of a radius of the shaft; 
 a stationary portion; 
 a liquid metal in a space between the rotating portion and the stationary portion; and 
 a sealing portion formed by a liquid metal vacuum/ambient fluid interface configured to form a vacuum first in a radial direction and second in an axial direction to prevent flow of the liquid metal from a housing to a vacuum/ambient portion using a surface tension of the liquid metal, wherein the flange portion forms a portion of the sealing portion. 
 
   
   
     23. A method for sealing an X-ray tube, the method comprising:
 providing a liquid metal to lubricate and/or cool a radially inner rotating portion of an X-ray tube, wherein said radially inner rotating portion is coupled to an anode of the X-ray tube, and wherein the rotating portion further comprises a shaft having a flange portion extending from an axis along a length of the shaft towards a direction of a radius of the shaft; and 
 configuring a non-contact seal in combination with the rotating portion to prevent fluid flow from the rotating portion to a vacuum portion, the non-contact seal having a radial vacuum interface formed by an axial clearance and an axial vacuum interface formed by a radial clearance together resisting flow of liquid metal, wherein the flange portion of the non-contact seal.